how to sort an arraylist in java

/**
 * @author lautturi.com
 * Java example: sort an arraylist in java
 */

import java.util.*;

public class Lautturi {

	public static void main(String[] args) {

		ArrayList<Integer> arrlist = new ArrayList<Integer>();
		arrlist.add(3);
		arrlist.add(7);
		arrlist.add(15);
		arrlist.add(8);
		arrlist.add(22);
		arrlist.add(12);

		System.out.println(arrlist);
		 Collections.sort(arrlist);
		System.out.println(arrlist);

	}
}

output:

[3, 7, 15, 8, 22, 12]
[3, 7, 8, 12, 15, 22]